GB880564A - A method and apparatus for wrapping bead wires for tyre covers with fabric ply loops - Google Patents

Abstract

880,564. Wrapping tyre bead cores. PIRELLI S.p.A. May 12, 1958 [May 14, 1957], No. 15156/58. Class 144 (1). A tyre bead core 24 is wrapped with a flipper strip by means of a drum 1 round which the flat strip plies are wrapped with the bead core centred thereon, the drum surface comprising an inflatable expansible tubular diaphragm 3 anchored at its side edges to end flanges 2 of the drum so that when inflated, the diaphragm expands radially on each side of the bead core to wrap the flipper plies therearound and the expansion of the diaphragm being guided by a hood 13 fixed at one end of the drum 1 and a hood 14 movable axially to abut the hood 13 and enclose the drum so that the parts of the expanded diaphragm on each side of the bead core are forced towards each other to complete the wrapping operation. As shown, the drum 1 comprises a rigid cylinder with end flanges 2 to which the edges of the diaphragm 3 are clamped by rings 5. The drum is mounted on a tubular shaft 7 forming a conduit for the inflating fluid of the diaphragm and rotatable by a motor 34. The shaft is journalled in a sleeve 31 on which is slidably mounted a ring 25 carrying bead locating arms 22 which project axially through holes in the adjacent fixed hood 13. The arms 22 have heads 23 normally housed in recesses in the hood 13 and the ring 25 is movable by a double-acting piston and cylinder 29, 30 to extend the arms 22 to locate the bead core 24 centrally of the drum. The fixed and movable hoods 13, 14 each comprise a conical side wall 15 and a cylindrical periphery 16. The hood 14 is spaced coaxially from the drum and is carried by a piston 19 slidable in a cylinder 20 for projection into a position abutting the fixed hood 13 as shown in broken lines in Fig. 1. In an alternative construction the drum comprises solely the diaphragm 3 anchored to end discs which are mutually approachable on expansion of the diaphragm.